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// Copyright (c) 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// range_map-inl.h: Range map implementation.
//
// See range_map.h for documentation.
//
// Author: Mark Mentovai

#ifndef PROCESSOR_RANGE_MAP_INL_H__
#define PROCESSOR_RANGE_MAP_INL_H__


#include "processor/range_map.h"


namespace google_airbag {


template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::StoreRange(const AddressType &base,
                                                  const AddressType &size,
                                                  const EntryType &entry) {
  AddressType high = base + size - 1;

  // Check for undersize or overflow.
  if (size <= 0 || high < base)
    return false;

  // Ensure that this range does not overlap with another one already in the
  // map.
  MapConstIterator iterator_base = map_.lower_bound(base);
  MapConstIterator iterator_high = map_.lower_bound(high);

  if (iterator_base != iterator_high) {
    // Some other range begins in the space used by this range.  It may be
    // contained within the space used by this range, or it may extend lower.
    // Regardless, it is an error.
    return false;
  }

  if (iterator_high != map_.end()) {
    if (iterator_high->second.base() <= high) {
      // The range above this one overlaps with this one.  It may fully
      // contain  this range, or it may begin within this range and extend
      // higher.  Regardless, it's an error.
      return false;
    }
  }

  // Store the range in the map by its high address, so that lower_bound can
  // be used to quickly locate a range by address.
  map_.insert(MapValue(high, Range(base, entry)));
  return true;
}


template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveRange(
    const AddressType &address, EntryType *entry,
    AddressType *entry_base, AddressType *entry_size) const {
  if (!entry)
    return false;

  MapConstIterator iterator = map_.lower_bound(address);
  if (iterator == map_.end())
    return false;

  // The map is keyed by the high address of each range, so |address| is
  // guaranteed to be lower than the range's high address.  If |range| is
  // not directly preceded by another range, it's possible for address to
  // be below the range's low address, though.  When that happens, address
  // references something not within any range, so return false.
  if (address < iterator->second.base())
    return false;

  *entry = iterator->second.entry();
  if (entry_base)
    *entry_base = iterator->second.base();
  if (entry_size)
    *entry_size = iterator->first - iterator->second.base() + 1;

  return true;
}


template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveNearestRange(
    const AddressType &address, EntryType *entry,
    AddressType *entry_base, AddressType *entry_size) const {
  if (!entry)
    return false;

  // If address is within a range, RetrieveRange can handle it.
  if (RetrieveRange(address, entry, entry_base, entry_size))
    return true;

  // upper_bound gives the first element whose key is greater than address,
  // but we want the first element whose key is less than or equal to address.
  // Decrement the iterator to get there, but not if the upper_bound already
  // points to the beginning of the map - in that case, address is lower than
  // the lowest stored key, so return false.
  MapConstIterator iterator = map_.upper_bound(address);
  if (iterator == map_.begin())
    return false;
  --iterator;

  *entry = iterator->second.entry();
  if (entry_base)
    *entry_base = iterator->first;
  if (entry_size)
    *entry_size = iterator->first - iterator->second.base() + 1;

  return true;
}


template<typename AddressType, typename EntryType>
void RangeMap<AddressType, EntryType>::Clear() {
  map_.clear();
}


}  // namespace google_airbag


#endif  // PROCESSOR_RANGE_MAP_INL_H__